Linux and sendfile

[Jeff Macdonald]

Hi all,
I'm hoping there are some fellow programmers here that have used the
sendfile system call. What I'm wondering is should I treat sendfile like
write when the out_fd is a socket. By that, I mean even if I specifiy N
count bytes, sendfile might only send < N bytes and if it does, I should
call sendfile again.

Here's the prototype:
ssize_t sendfile(int out_fd, int in_fd, off_t *offset, size_t count);